Textile Monopole Antenna Research Articles

A Compact Wearable Textile Antenna for NB-IoT and ISM Band Patient Tracking Applications.

This paper proposes a novel multi-band textile monopole antenna for patient tracking applications. The designed antenna has compact footprints (0.13λ02) and works in the narrow band-internet of things (NB-IoT) 1.8 GHz, radio frequency identification (RFID), and industrial, scientific, and medical (ISM) 2.45 GHz and 5.8 GHz bands. The impedance bandwidths and gain of the antenna at 1.8 GHz, 2.45 GHz, and 5.8 GHz are 310 MHz, 960 MHz, and 1140 MHz; 3.7 dBi, 5.3 dBi, and 9.6 dBi, respectively. Also, the antenna's behavior is checked on different body parts of the human body in various bending scenarios. As per the evaluated link budget, the designed antenna can easily communicate up to 100 m of distance. The specific absorption rate values of the designed antenna are also within acceptable limits as per the (FCC/ICNIRP) standards at the reported frequency bands. Unlike traditional rigid antennas, the proposed textile antenna is non-intrusive, enhancing user safety and comfort. The denim material makes it comfortable for extended wear, reducing the risk of skin irritation. It can also withstand regular wear and tear, including stretching and bending. The presented denim-based antenna can be seamlessly integrated into clothing and accessories, making it less obtrusive and more aesthetically pleasing.

A Compact Textile Monopole Antenna for Monitoring the Healing of Bone Fractures Using Un-Supervised Machine Learning Algorithm

A Compact Textile Monopole Antenna for Monitoring the Healing of Bone Fractures Using Un-Supervised Machine Learning Algorithm

Miniaturized Circularly Polarized UWB Antenna for Body Centric Communication

A compact body-worn circular polarized textile monopole antenna for wearable applications is reported. The proposed antenna is fabricated on a jean fabric providing flexibility, lightweight, and easy integration into human clothes. The overall size of the proposed antenna is <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$25\times 30\times1.4$ </tex-math></inline-formula> mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> . Circular polarization (CP) is advantageous for on-body communication as it provides features, such as multipath immunity, suppressing interferences, and enables better link connectivity between the sensor nodes. The proposed antenna achieves the CP using an asymmetric stepped L-shaped ground plane and through the incorporation of a cross-shaped stub in the radiator. The single-fed octagonal strip monopole antenna provides good impedance matching over the entire ultrawide frequency range from 3.09 to 11 GHz. Simulation results are in good correlation with the measured results. The axial ratio bandwidth <3 dB is achieved in the frequency range of 3.4–10 GHz. Gain and efficiency obtained are about 2.3-4.4 dBi and 65%–82% at the said frequency range, respectively. Structural deformation is performed to analyze the flexibility of the proposed antenna. The simulated SAR values follow the FCC limit making it most suitable for wearable applications.

Determination of Salinity and Sugar Concentration by Means of a Circular-Ring Monopole Textile Antenna-Based Sensor

This paper presents a monopole antenna-based sensor for measuring different amounts and concentrations of salt and sugar in water. The proposed antenna sensor consists of a textile monopole antenna with circular-ring and partial ground plane. It is implemented by means of embroidery on a felt textile substrate and it resonates at 2.4 GHz. The textile substrate can absorb liquids through the sensing area incorporated within the monopole antenna structure. Therefore, the substrate dielectric properties are changed according to the liquid properties of the absorbed solution. The proposed antenna sensor uses microwave signals to track different amount and concentrations of salt and sugar in terms of the magnitude of the return loss and resonance frequency shift. The measurements are recorded and compared before and after applying different solutions. The rinsing reliability of the proposed antenna sensor has been also studied. The proposed antenna sensor demonstrates a high sensitivity of 800 MHz/mL with a good correlation with the linear fit ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${R}^{2}= 0.9737$ </tex-math></inline-formula> ) and 550 MHz/mL with linear response ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${R}^{2}= 0.9135$ </tex-math></inline-formula> ) for 5% salt and sugar concentration solutions, respectively. To the best of our knowledge, this article demonstrates for the first time the capability of a fully-textile antenna sensor to detect different amounts and concentrations of salt and sugar using microwave signals.

Textile Antenna-Sensor for In Vitro Diagnostics of Diabetes

In this paper, a feasibility study of a microwave antenna-based sensor is proposed for in vitro experiments for monitoring blood glucose levels. The proposed device consists of a square-ring incorporated within a fully textile monopole antenna to absorb and sense different glucose concentrations, covering patients with different diabetic conditions. The designed antenna-sensor is optimized to operate at 2.4 GHz. The sensing principle is based on the resonance frequency shift of the reflection response of the antenna-based sensor under different glucose levels. The experiments were carried out with blood mimicking by means of aqueous solutions, using D(+)- glucose/water in different concentrations for various diabetic conditions of type-2 diabetes. The performance of the embroidered antenna-based sensor is characterized and validated using a convenient setup for in vitro measurements. The results demonstrated the ability of the proposed antenna-based sensor to cover all the glucose levels of the diabetes range, including hypoglycemia (10–70 mg/dL), normoglycemia (80–110 mg/dL) and hyperglycemia (130–190 mg/dL) with a sensitivity of 350 kHz/(mg/dL). Besides its ability to detect different glucose concentrations of various diabetic conditions, the proposed antenna-sensor presents diverse features such as a simplistic design, compact size, wearability and low cost. The proposed textile device demonstrates a proof of concept for efficient in vitro blood glucose level measurements and diagnostics of diabetes.

Embroidered Textile Antennas: Influence of Moisture in Communication and Sensor Applications.

Moisture causes detuning and increased losses in textile antennas, and it affects resonant and wideband textile antennas differently. In this work, we studied the effect of moisture on a resonant textile planar inverted-F antenna (PIFA) and a wideband textile monopole antenna. Both antennas were manufactured by embroidering conductive yarn in denim textile. The input reflection coefficient, antenna gain, and gain patterns were measured on both antennas for different moisture contents. The results show that wideband antennas are less affected by moisture in comparison with resonant antennas. For communications applications, large moisture content in the textile antenna should be avoided; therefore a flexible, textile-based waterproofing antenna cover was proposed, manufactured, and tested. On the other hand, the effect of antenna detuning by moisture can be used for moisture-sensing application. This concept was demonstrated on the resonant textile PIFA in transmission and reflection setups, showing that the reflection setup gives better results.

SAR Evaluation of Metallic Loop-like Accessory Effect of Broadband Wearable Planar Monopole Textile Antenna

This paper presents the investigation influence of the common metallic loop like accessory on Specific Absorption Rate (SAR) averaged over 10g and 1 g tissue.The simulations were made by means CST Microwave Studio software at frequencies 2.45GHz and 2.6GHz. Numerical analysis conducted using broadband textile monopole antenna (TM) with variations of orientation and distance showed that the SAR value increased when the antenna horizontally polarized.This is up to 80% more than vertically polarized TM placed closest item to 2mm.

Design of flexible textile antenna using FR4, jeans cotton and teflon substrates

In modern technology, reduction in size and complexity of the antenna are the primary objective of recent research. This reduced size antenna is the boon in medical applications. This paper proposes monopole antenna which constitutes a simple structure and light-weight with a use of textile substrate. The prototype designed in this paper will be used for Body Centric Wireless Communications operating in 2.45 GHz Industrial, Scientific and Medical band. Return loss of − 10 dB and wide bandwidth against the conventional monopole antenna is achieved in the proposed system. Besides, a satisfactory gain characteristic has been obtained using wearable textile monopole antenna when it is compared to the conventional monopole antenna.

The Effects of Metallic Loop-Like Accessory Worn on the Human Body on SAR at 2.45 GHz

This paper presents the Specific Absorption Rates (SAR) in the human body with a monopole antenna. The distance between the antenna and the body were varied at different distances. The parameters (er, σ) used in the human body set according to the standard tissue equivalent liquids recommended by the IEEE and FCC. The simulations were made by means of CST Microwave Studio software at frequencies of 2.45GHz .The effect of the body on the SAR calculation in the body were measured. The SAR values were recorded in term of SAR for 10g of tissue. The TM is positioned against the metallic loop-like accessory, place on the left wrist of the generic arm at a varied distance from the cylindrical phantom. Numerical analysis conducted using a broadband textile monopole antenna (TM) with variations of orientation and distance showed that SAR values increased when the TM is horizontally polarized.

Evaluation of a broadband textile monopole antenna performance for subject-specific on-body applications

The human body characteristics with different dimensions and tissue properties are one of the major factors in influencing the on-body radio propagation channel characteristics. A broadband textile monopole antenna operating at 2.45 GHz is evaluated to validate its performance on different subjects’ characteristics. The results show that the textile monopole antenna is sufficiently robust against the variations introduced by the body up to 0.9 and 0.2% changes in the antenna’s impedance matching level and resonant frequency shift when evaluated 10 mm from the body.

Wearable monopole zip antenna

The design of a novel textile monopole antenna based on a zip at 2.5 GHz is presented. A prototype is manufactured and characterised based on return loss and radiation pattern. The bandwidth and radiation characteristics obtained make the zip antenna suitable to be used for WiFi applications in the band from 2.4 to 2.7 GHz.